<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        /*z-index 取值整数数字。取值越大，默认值是0. 显示顺序越靠上。设置行内块的优先级*/
        .one {
            position: absolute;
            z-index: 1;
            left: 50px;
            top: 50px;
            width: 300px;
            height: 300px;
            background-color: pink;
        }

        .two {
            position: absolute;
            left: 150px;
            top: 150px;
            width: 300px;
            height: 300px;
            background-color: skyblue;
        }
    </style>
</head>
<body>
<!--默认情况下：后来者居上-->
<div class="one">one</div>
<div class="two">two</div>
</body>
</html>